Simultaneous Multiparametric Estimation of AVM Hemodynamics Using MR Fingerprinting Arterial Spin-Labeling.

Background and purpose: Accurate hemodynamic characterization of cerebral AVMs is critical for treatment-planning, risk-stratification, and posttreatment monitoring but remains challenging due to their abnormal angioarchitecture. MR-fingerprinting (MRF) arterial spin-labeling (ASL) is a novel, noninvasive technique that enables simultaneous quantification of CBF, arterial CBV (aCBV), and bolus-arrival time (BAT) within a single 5-minute scan. This study evaluates the feasibility of MRF-ASL in assessing AVM hemodynamics and compares its sensitivity for AVM detection with CBF measurements obtained using single-delay pseudocontinuous ASL (pCASL).

Materials and methods: Patients with DSA-confirmed AVMs were scanned on a 3T MRI system. Imaging protocols included MRF-ASL, standard single-delay pCASL, and T2-weighted MRI. MRF-ASL simultaneously-derived CBF, aCBV, and BAT, with CBF estimated using 2 kinetic models: a 1-compartment model, which reflects combined tissue and arterial contributions, and a 2-compartment model, which separates arterial signal from tissue perfusion. Regions of interest were manually drawn over the AVM nidus and contralateral nonaffected tissue. MRF-ASL parameters and pCASL-derived CBF were compared between the AVM nidus and nonaffected tissue. Additionally, linear regression analyses were conducted to examine the relationships among MRF-ASL parameters, single-delay pCASL CBF, and the Spetzler-Martin (SM) grade.

Results: Six patients with AVMs with SM grades ranging from 1 to 5 were included in this study. MRF-ASL parameters revealed significantly elevated CBF_{1-compartment} (AVM, 129.3 [SD, 21.5 mL/100 g/minute] versus nonaffected, 51.6 [SD, 23.9 mL/100 g/minute], P = .03), CBF_{2-compartment} (AVM, 109.8 [SD, 24.4 mL/100 g/minute] versus nonaffected, 36.6 [SD, 18.6 mL/100 g/minute], P = .03), aCBV (AVM, 7.0 [SD, 4.5%] versus nonaffected, 0.6 [SD, 0.4%], P = .03), and shortened BAT (AVM, 784 [SD, 337 ms] versus nonaffected, 1099 [SD, 500 ms], P = .03) in the AVM nidus compared with contralateral nonaffected tissue in the same patient. In contrast, no significant difference was observed for pCASL CBF (AVM, 47.5 [SD, 49.2 mL/100 g/minute] versus nonaffected, 39.4 [SD, 14.0 mL/100 g/minute], P = .44). A significant positive correlation was identified between the SM grade and both CBF_{2-compartment} (P = .006) and aCBV (P = .005). No association was found for CBF_{1-compartment} (P = .12), BAT (P = .15), or pCASL CBF (P = .13).

Conclusions: In our preliminary study, MRF-ASL has the potential to provide comprehensive and multiparametric evaluation of AVM hemodynamics, demonstrating superior sensitivity for detecting AVM abnormalities compared with single-delay pCASL. These findings show the feasibility of MRF-ASL as a potentially useful tool for noninvasive characterization and monitoring of AVMs.